From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CDF4C432C1 for ; Wed, 25 Sep 2019 06:52:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C9CE217F4 for ; Wed, 25 Sep 2019 06:52:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569394374; bh=vem+Ya5hTrdZxovEGCRBzOmw2a7tVEJFMEobzQZHFcw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=IHJT91LsSlV0JegRJnVKb16CA3ArlndktGci/3qMvppV4RyLY05yK5mKNk2j6WsM1 PEvnrEI0NDeIz+O9n5TEiC/OwkyXpbXbAWaS5YzSBMPlHFS4En1PMjb4z+mCmzpHtp 3xnwbrNn/abazuFFuTvEhxl1M7p3bF4fUcR3C6Hc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2442376AbfIYGwx (ORCPT ); Wed, 25 Sep 2019 02:52:53 -0400 Received: from mx2.suse.de ([195.135.220.15]:45958 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2436671AbfIYGww (ORCPT ); Wed, 25 Sep 2019 02:52:52 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 49E1FB044; Wed, 25 Sep 2019 06:52:51 +0000 (UTC) Date: Wed, 25 Sep 2019 08:52:48 +0200 From: Michal Hocko To: Hillf Danton Cc: Roman Gushchin , Johannes Weiner , Andrew Morton , linux , linux-mm , Shakeel Butt , Matthew Wilcox Subject: Re: [RFC] mm: memcg: add priority for soft limit reclaiming Message-ID: <20190925065248.GF23050@dhcp22.suse.cz> References: <20190924073642.3224-1-hdanton@sina.com> <20190924133016.GT23050@dhcp22.suse.cz> <20190925023530.6364-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190925023530.6364-1-hdanton@sina.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 25-09-19 10:35:30, Hillf Danton wrote: > > On Tue, 24 Sep 2019 17:23:35 +0000 from Roman Gushchin > > > > On Tue, Sep 24, 2019 at 03:30:16PM +0200, Michal Hocko wrote: > > > > > > But really, make sure you look into the existing feature set that memcg > > > v2 provides already and come back if you find it unsuitable and we can > > > move from there. Soft limit reclaim is dead and we should let it RIP. > > > > Can't agree more here. > > > > Cgroup v2 memory protection mechanisms (memory.low/min) should perfectly > > solve the described problem. If not, let's fix them rather than extend soft > > reclaim which is already dead. > > > Hehe, IIUC memory.low/min is essentially drawing a line that reclaimers > would try their best not to cross. Page preemption OTOH is near ten miles > away from that line though it is now on the shoulder of soft reclaiming. Dynamic low limit tuning would achieve exactly what you are after - aka prioritizing some memory consumers over others. -- Michal Hocko SUSE Labs